Barbour said it was important to select a person with Lott's "conservative values" and who would be able to work with Mississippi Sen. Sen. Thad Cochran, also a Republican.

Wicker, 56, will serve until a special election is held. He is expected to be a candidate in the special election, which Barbour has scheduled for Nov. 4.

Wicker had been mentioned as a possible successor since Lott's resignation earlier in December after serving one year of a six-year term. Lott's term runs through 2012.

Wicker was elected to the U.S. House in 1994 to succeed the late Rep. Jamie Whitten. He has been re-elected six times from the 1st District in north Mississippi. Wicker was resigning from the U.S. House.

Lott served 16 years in the U.S. House before moving to the Senate in 1988. Lott announced in November that he would resign before the end of the year. He resigned Dec. 19 after Congress wrapped up its work for the year.

Lott, 66, said he wants to spend more time with his family and to pursue other job opportunities, possibly teaching. He ruled out any health concerns, but said it's time for a younger voice to represent Mississippi in the Senate.